Intermittent Starter Problem

About 3 months ago I tried to start my jeep and the starter was dragging like the battery was low. I turned the key off, waited a few seconds, and tried again. It started fine. It only happened a few times, off and on for a while but it has gotten worse in the last two weeks. For a while, it would only drag if I had my foot on the brake pedal. So I got in a habit of never pushing the brake in when I started it. Now it is doing it about 60% of the time when I try to start it. I've searched some other forums and no one seems to have an answer even though it seems to be happening to several jeeps. Here's what I've found:

* Possibly a bad battery (even if it tests good)
* Faulty starter
* Faulty relay
* Sway bar harness??

The engine will crank. It just sounds like the battery is dead. If the battery is bad, could it really have been going on for 3 months? I hate to start replacing parts randomly. Where would you suggest I start: battery, starter, relay?

Specs:
2010 JK, 4-door
Stock 3.8L engine
Automatic
Winch
50" LED Bar

I had the same problem. I sprayed (2 hits) of starting fluid into the intake and it started right up. I knew mine wasn't the starter/battery because I had them replaced recently.

Sounds like a bad ground to me had this happen in my 02 Dakota. Ended up being a bad negative cable, the end @ the ground looked fine but when I took it off it was so corroded it was ridiculous and the bolt had come loose also....